In the USA, a significant proportion of the new corona infections can be traced back to the XBB.1.5 variant, which has only recently been discovered. The US health authority CDC estimates that in the week before the turn of the year XBB.1.5 was behind around 40.5 percent of all new infections. The variant could be more easily transferrable, according to the CDC. “We have been monitoring XBB.1.5 since mid-November, and its frequency has doubled approximately every week,” Richard Neher, head of the research group Evolution of Viruses and Bacteria at the Biozentrum of the University of Basel, told the German Press Agency.
The variant is characterized by the mutation F486P in the so-called spike protein. This is the part of the virus that it uses to attach to human cells. “This mutation may improve binding to the ACE2 receptor on human cells. What exactly this means is not clear,” emphasized Neher. He is not aware of any indications that XBB.1.5 leads to more severe disease progressions. Federal Minister of Health Karl Lauterbach (SPD) wrote about the US numbers on Twitter: “You have to watch that.”
The variant XBB.1.5, which is related to the omicron subvariant BA.2, is not mentioned in the latest Corona weekly report from the Robert Koch Institute. However, the report was published on December 22nd.